Re:Cyclic dependencies are evil (2013)
by IggleSniggle on Saturday January 30, 2021 @06:36PM
(#25974177)
Yes, there is a single transactional global state.
There is always state somewhere, the question is where it should be.
Global state is the input to the program, and a new global state is the output. Given identical inputs, it will always produce the same output.
This is the entire principle behind ACID, and mutation of global state is a common approach for functional programmers regardless of whether they they are using a DB or not.
If a DB were not fully transactional, or if your queries of the DB are not deterministic themselves, then we’ve moved out of functional territory.
There is always state somewhere, the question is where it should be.
Global state is the input to the program, and a new global state is the output. Given identical inputs, it will always produce the same output.
This is the entire principle behind ACID, and mutation of global state is a common approach for functional programmers regardless of whether they they are using a DB or not.
If a DB were not fully transactional, or if your queries of the DB are not deterministic themselves, then we’ve moved out of functional territory.